Approve nintex workflow from shared mail box?

I have a nintex workflow setup for approval process that goes to a shared mail box. When the users of the shared mail box click on the link to approve, they get a message like "You are not authorized to respond to this task". Kindly advise.

Note: They however able to open the workflow history link and are able to click on Respond to this task. That works fine. But approval link in mail notification is not working.

I know this is a much older question, and I hope that you were able to resolve this issue by now, but I wanted to share something that we did to avoid this.

We created a SharePoint User group with the users that need to be assigned to the task as well as the shared mailbox. Then, in the task, select the newly created SP user group as the assignee in the task. Be sure to keep the "Create individual tasks for all group members" unchecked so that it creates a single task that everyone can then access.

I wonder if you added a sharepoint group with the sole occupant being the shared mailbox account, whether adding that sharepoint group to the task assignee would work? It sounds like the users that share the mailbox have the correct ownership of the task if they can action it from the workflow history.

Also maybe try coping the link out of the email and directly pasting it into a browser window. It seems strange that you say the link is the same in both the email and the workflow history. If that is the case it almost sounds like the clicking of the link in the email is opening the task under different credentials.

The concept here is that users do not want their own mail box to spammed with notification mails. So thats why they brought in shared mailbox to the picture. In the assignees field I have the shared mail id alone. No other group is present along with this mail id.

I am going to give it a try. Copy the link from mail and paste it into browser. Lets see what happens

I know this is a much older question, and I hope that you were able to resolve this issue by now, but I wanted to share something that we did to avoid this.

We created a SharePoint User group with the users that need to be assigned to the task as well as the shared mailbox. Then, in the task, select the newly created SP user group as the assignee in the task. Be sure to keep the "Create individual tasks for all group members" unchecked so that it creates a single task that everyone can then access.